猪苓多糖对小鼠腹腔巨噬细胞诱导型一氧化氮合酶活性及mRNA表达的影响

Effects of polyporus polysaccharide on activity and mRNA expression of inducible nitric oxide synthase in peritoneal macrophages of mice

目的:探讨猪苓多糖(polyporuspolysaccharide,PPS)的免疫调节作用和抗肿瘤作用机制。方法:采用Griess反应、荧光法和RT-PCR分别测定不同剂量的PPS作用下小鼠腹腔巨噬细胞的NO生成量、iNOs活性及mRNA表达水平。结果:PPS能使小鼠腹腔巨噬细胞iNOS活性增高,并呈作用剂量依赖关系,PPS能刺激小鼠腹腔巨噬细胞iNOSmRNA表达。结论:PPS刺激小鼠腹腔巨噬细胞NO合成的调节可发生在iNOS的转录水平,从而刺激巨噬细胞NO大量合成与释放。PPS的免疫调节作用和抗肿瘤作用机制可能与PPS刺激巨噬细胞iNOS从头合成从而增加NO生成有关。

Objective:To study the mechanisms of the antitumor and immunoregulation functions of polyporus polysaccharide (PPS). Methods: The production of nitric oxide (NO), the activity and mRNA expression of inducible nitric oxide synthase (iNOS) in peritoneal macrophages of mice administered with different dose of PPS were observed by Griess reaction, fluorime-try assay and RT-PCR, respectively. Results:PPS could elevate the iNOS activity with dose-dependence and stimulate the iNOS mRNA expression of peritoneal macrophages in mice. Conclusion: The regulation of PPS on the production of NO in peritoneal macrophages of mice may occur at transcriptional level of iNOS. This indicates that the mechanism of PPS's antitumor and immunoregulation functions may be related to increasing NO output of macrophages through stimulating iNOS's denovo synthe-